Innertkirchen – Mettlen grid project

The 61-kilometre line section between Innertkirchen and Mettlen is to be replaced and upgraded from 220 to 380 kilovolts. Swissgrid reviewed three planning territories for the line route: Glaubenberg (near the existing line), Pilatus (through the Sarneraa Valley) and Entlebuch (via Sörenberg and Entlebuch).

Your contact for this grid project

Joshu Jullier
Joshu Jullier

Phone +41 58 580 21 11
info@swissgrid.ch


The most important facts at a glance

  • Most of the line between Innertkirchen and Mettlen is over 70 years old and needs to be brought in line with the current state of the art.
  • At the same time, the line will be upgraded from today's 220 kilovolts to 380 kilovolts. This is necessary to ensure the transportation of the growing volume of electricity generated by the Oberhasli power plants and the hydroelectric power plants in Valais and Ticino to the Swiss Central Plateau.
  • In mid-2021, Swissgrid applied to the Swiss Federal Office of Energy (SFOE) to establish a planning territory between Innertkirchen and Mettlen. Planning territories are geographic areas within which a planning corridor, including transmission technology (underground cable, overhead line or combined options), can then be chosen at a subsequent stage of the project.
  • Swissgrid examined three possible planning territories: the Glaubenberg planning territory near the existing line as well as the Pilatus (through the Sarneraa Valley) and Entlebuch (via Sörenberg and Entlebuch) planning territories.
  • Each of the submitted options has certain pros and cons. From Swissgrid’s perspective, the Glaubenberg planning territory is the best option.
  • Next, a monitoring group appointed by the SFOE will discuss and assess the planning territories.
  • The Federal Council is expected to decide on the planning territory by autumn 2023.

Project

Current situation

Most of the 61-kilometre extra-high-voltage line between Innertkirchen and Mettlen is over 70 years old and needs to be replaced. At the same time, the line voltage will be upgraded from the existing 220 kV to 380 kV along its entire length. This upgrade is an important project within Swissgrid’s implementation of «Strategic Grid 2025».

Why the project is necessary

Expanding the amount of electricity produced from hydropower is a central pillar of the Energy Strategy 2050. The increase in capacity between Innertkirchen and Mettlen is necessary to be able to transport the growing volume of electricity generated by the Oberhasli power plants and the Valais and Ticino hydroelectric power plants to the Swiss Central Plateau. Distributing energy flows along several north-south axes also increases grid stability. The Innertkirchen – Mettlen grid project therefore not only supports the expansion of renewable hydropower, it also ensures Switzerland’s security of supply.

The existing extra-high-voltage line between Innertkirchen and Mettlen leads over the Glaubenberg Pass.
The existing extra-high-voltage line between Innertkirchen and Mettlen leads over the Glaubenberg Pass.

Three possible planning territories

In mid-2021, Swissgrid applied to the Swiss Federal Office of Energy to establish a planning territory between Innertkirchen and Mettlen in the federal government’s sectoral plan for transmission lines. Planning territories are geographic areas within which a planning corridor, including transmission technology (underground cable, overhead line or combined options), can then be chosen at a subsequent stage of the project. To this end, Swissgrid examined three partly overlapping planning territories.

Overview of the three planning territories
Overview of the three planning territories

Glaubenberg planning territory

This planning territory largely follows the existing 220 kV line and leads from Innertkirchen via Giswil and Glaubenberg to Malters and then on towards Mettlen. The greatest challenge of this option is the “Glaubenberg” flysch moor landscape. No overhead lines or underground cables installed using open trenching techniques are permitted in this landscape of national importance. Swissgrid therefore proposes to tunnel under Glaubenberg.

Pilatus planning territory

The second option leads from Giswil through the Sarneraa Valley and then west or east of Pilatus to Littau and Mettlen. The main challenges presented by this option are the large settlement areas (Giswil, Sarnen, Alpnach, Hergiswil and Kriens), the scattered settlements, and the limitations imposed by the obstacles of the Kägiswil, Alpnach and Buochs airfields and the nationally protected Pilatus region.

Entlebuch planning territory

As a third alternative, a planning territory could lead west from Giswil through Entlebuch to Mettlen. This option crosses through the UNESCO Entlebuch biosphere reserve and is much longer than the two other evaluated planning territories.

Swissgrid recommends the Glaubenberg planning territory

Both of the submitted variants have specific advantages and disadvantages with respect to regional planning, the environment, technology and economic viability. From Swissgrid’s perspective, the Glaubenberg planning territory provides is the best of the three options. Firstly, it touches fewer settlement areas and involves fewer obstacles than the other options. Secondly, it is much shorter than the planning territory via Entlebuch and so has less of an impact on the ground, the natural environment and the landscape, requires less construction material and has lower energy losses and costs.

Two sections are considered separately

The section between Mettlen and Hellbühl (Littau) is considered separately. It was upgraded to 380 kV in 1990, but is currently operating at just 220 kV. The Innertkirchen – Mettlen and Bickigen – Mettlen lines approach one another to the west of Rothenburg, from where they are bundled in the section to Mettlen. With this in mind, it makes sense to consider both lines together in this section in order to provide permanent relief for the settlement area. Swissgrid will therefore review the line routing in this area as part of the planned Bickigen – Mettlen line renovation. The line lead-in for the Innertkirchen substation will be considered separately within the Innertkirchen – Mettlen sectoral plan process: two additional transmission lines run parallel to the Innertkirchen – Mettlen line along a roughly two-kilometre section. As all three lines pass through the settlement area, the only option in this section is to install an underground cable in a tunnel.


Next steps

In the next stage of the sectoral plan process, a monitoring group appointed by the Swiss Federal Office of Energy (SFOE) will come together with the federal authorities, the affected cantons and environmental associations to discuss and assess the planning territory options developed by Swissgrid. The monitoring group’s recommendation will then be taken forward to the public consultation stage. The Federal Council is expected to decide on the planning territory between Innertkirchen and Mettlen by autumn 2023. Swissgrid will then set out various planning corridors for each transmission technology (overhead line, underground cable or combined versions) within this planning territory and submit these to the SFOE monitoring group. The corridor will then be stipulated by the Federal Council. Ideally, the renewal of the Innertkirchen – Mettlen extra-high-voltage grid will be completed by 2035. After that, the existing line, parts of which run through the settlement area, will be removed.

Schedule in the best case without appeal to the courts
Schedule in the best case without appeal to the courts

Information events

In Malters and Giswil

Dialogue with citizens, municipalities, authorities and associations is very important to Swissgrid. Swissgrid will be holding information events on the project on Monday, 22 November 2021 at 6.30 p.m. in Malters and on Thursday, 25 November 2021 at 6.30 p.m. in Giswil. Admission is only possible with a COVID-19 certificate. There are a limited number of spaces.


Downloads


Additional information

  • Approval process

    Swissgrid is responsible for the project planning for and implementation of the transmission lines.

    Learn more

  • Emissions

    It is hard to imagine our daily life without the numerous electronic gadgets and tools. However, we are much less aware that electric and magnetic fields are formed everywhere electricity is present: including in the generation, transmission and distribution of electric energy.

    Learn more

  • Grid technologies

    The decision on whether to install a high-voltage line as an overhead line or as an underground cable is based on objective criteria. That's why Swissgrid checks the cable and overhead line options for every grid project.

    Learn more

Contact

Title

Please select a title.

Please enter your first name.

Please enter your last name.

Please enter a valid e-mail address.

Please enter your message.

Please click the checkbox.

Contact

Title

Please select a title.

Please enter your first name.

Please enter your last name.

Please enter a valid e-mail address.

Please enter your message.

Please click the checkbox.